It is unclear in what capacity Lambert will be joining the Fox musical comedy, as the network has yet to announce whether it will be in a regular, recurring or guest spot role.

Last season, "Glee" brought on season eleven "Idol" runner-up Jessica Sanchez in a recurring role. Other major guest stars included Kate Hudson and Sarah Jessica Parker, who were part of story lines connected with the show's stars Lea Michele and Chris Colfer in their post-high school New York City lives. Season five premieres September 19th on Fox.